Magnetic anastomosis devices (MADs) are currently used to create a channel between two viscera for the purpose of redirecting bodily fluids. For example, intestinal contents or bile may be redirected in patients who have developed an obstruction of the bowel or bile duct due to such conditions as tumor, ulcer, inflammatory strictures or trauma. With reference to FIG. 1, the relative positions of several organs of the abdominal cavity are shown, including the gall bladder 10, the common bile duct 12, the stomach 14, the duodenum 16 and the jejunum 18 of the small intestine. Inflammatory strictures 20, 22 of the jejunum 18 and bowel duct 12 are shown by the dotted lines in FIG. 1.
A magnetic anastomosis device (MAD) 30 has been depicted in FIG. 2, the details of which may be found in U.S. Pat. No. 5,690,656, the disclosure of which is incorporated herein by reference in its entirety. Generally, the MAD 30 includes first and second magnet assemblies 30a, 30b comprising magnetic cores 36a, 36b which are surrounded by thin metal rims 38a, 38b. Due to the magnetic attraction between the two magnetic cores 36a, 36b, the walls 32, 34 of two adjacent viscera may be sandwiched and compressed between the magnet assemblies 30a, 30b, resulting in ischemic necrosis of the walls 32, 34 to produce an anastamosis between the two viscera. With reference back to FIG. 1, the two viscera may comprise the jejunum 18 and the stomach 14, the bowel duct 12 and the duodenum 16, or various other combinations.
Historically, MADs have been delivered through surgical intervention such as laparotomy, which of course is invasive and carries its own risks. The exemplary self-centering MAD of U.S. Pat. No. 5,690,656 permit delivery of the device over a wire guide and through the oral cavity, and typically under fluoroscopy. Alternatively, delivery can be accomplished by simply swallowing the magnet assemblies of the MAD and using massage under fluoroscopy to center the two magnet assemblies. Finally, delivery of the magnet assemblies has occasionally been performed endoscopically with grasping forceps, which can be time consuming and difficult. Removal of the MAD is typically accomplished allowing the magnet assemblies to pass through the gastrointestinal track naturally, or more typically with a follow-up endoscopic procedure using grasping forceps. Unfortunately, the relatively large size of the magnet assemblies can make delivery and retrieval complicated. In fact, balloon dilation of bodily lumens is often required in order to deliver the magnet assemblies to the desired location. Likewise, the size of bodily lumens is often the limiting factor in the size of the magnet assemblies that can be delivered and deployed.